Electron discharge device



Patented Feb. 25, 1947 2,416,318 ELEc'rnoN DISCHARGE DEVICE William Hotlne, Bayville, N. Ii., asslgnor to Federal Telephoneeand Radio Corporation, a

corporation o! Delaware Appucauonaugust 1s, 1942, sei-m1 No. 454,958

(ci. 25o-27.5)

Claims.

This invention relates` to electron discharge devices and method of ladjusting same and more particularly to such a device whose electrodes may be adjusted for proper inter-electrode capacitance after assembly.

An object of this invention is to provide a novel electron discharge device having adjustable electrodes.

Another object of this invention is to 'provide a novel metlodA for accurately adjusting the inter-electrode capacitance of electron discharge devices.

Still another object of this invention is the provision of a novel stretching tool for adjusting the position of the electrodes within an electron discharge device. Y

A further object of this invention is to provide an electron discharge device in which some of the electrodes may be longitudinally stretched for the purpose of adjusting the inter-electrode capacities.

A more specific aspect of the invention lies in the method of longitudinally adjusting the position of the electrodes in an electron discharge device by the insertion of a stretching tool, and stretching such electrodes by this tool until a 4desired predetermined inter-electrode capacity is measured. E

Embodiments of a tube formed in accordance with the present invention, and my novel method for adjusting the inter-electrode capacities thereof, will be more clearly described below, and preierred embodiments are illustrated in the `attached drawings, in which:

Fig. 1 is a longitudinal cross-sectional view of an electron discharge device constructed in accordance with the present invention;

Fig. 2 is a. longitudinal cross-sectional view of a tool which may be used to adjust the electrodes of the device illustrated in Fig. 1;

Fig. 3 is a cross-sectional view of the tool illustrated in Fig. 2, taken along the line 3-3; and

Fig. 4 is a partial cross-sectional view of the device illustrated in Fig. 1, showing the. tool inserted within an electrode for stretchingthe same.

The electron discharge device I0 shown in Fig. 1 is of a. generally well-known configuration, and may be a triode having an anode I2, a cathode electrode I4, and a grid I6. A suitable envelope I8 surrounds the anode I2, while an envelope 28 surrounds the Icathode I4, the grid I8 inv this case forming the interconnecting means between the two envelopes.

2 Considering ilrst,k by way of example, the anod l2 constructed in accordance with the present invention, it will be noted that this anode is formed with a head portion 22 in juxtaposition with the grid I6, and a supporting base 24 illustrated as being corrugated in the form of a bellows. 'A collar 26 is preferably attached at the bottom of the base 24 for a, purpose to be described hereinafter. The form of electrode just described is such that while the corrugated thin-walled base 24 is sufficiently strong to yproperly support the anode head 22, at the same time the distance be- I tween the head 22 and grid I6 may be adjusted l by stretching the anode through expansion of the base 24. of the type described are generallymade of copper which will permit a certain amount of stretching when a corrugated section such as base 24 is used, and since copper of the form used has practically no resiliency, the anode I2 will retain its position relatively to the grid I6 after the corrugated section has been stretched the desired amount.

` A tool suitable for stretching an electrode such as anode I2 of Fig. 1, is generally indicated at 30 in Figs. 2 and 3. This preferred form of tool may consist of an A'internal threaded sleeve 32 supporting an externally threaded rod 34 upon one end of which is mounted a preferably cupshaped plunger 36, attached to the rod 34 as by pivot pin or rivet 38. A handle 33 at the other end of the rod may be used to rotate the latter in the sleeve 32 and move the plunger 36 longitudinally relatively thereto. Slidably mounted on the sleeve 32 is a second sleeve 40 which is split 'for the greater part of its length to form ilngers 42 upon whose outer ends are formed dogs 44. The periphery of the solid portion of the sleeve 40is threaded and supports a nut 48, one end of which bears against a collar 46 attached in any suitable manner to the proper end of the sleeve 32. Accordingly, rotation of the nut 48 bearing against the collar 46 will longitudinally slide the sleeve 40 relatively to the sleeve 32, suitable means (not shown) being provided to prevent relative rotation between the sleeves. The end of the sleeve 32 adjacent the dogs 44 is formed with a conical surface 49 upon which the dogs 44 are supported. It will therefore be seen that Anodes in electron discharge devices y adjust the electrodes of the electron discharge device of Fig. 1 is clearly illustrated in Fig. 4

whichv shows such a tool mounted in stretchingposition within the anode I2. It will be noted that in thiscase the plunger 36 abuts against the inner end of the anode head 22, this plunger Fig. 4 it will be'obvious to those skilled in this art that upon rotation of the handle 39 of tool 36, the plunger 36 will be moved longitudinally forwardlyVpushing out the anode head 22 and stretching the corrugated base 24. The capacitance between the grid I6 and the anode I2 may, at this time, be measured by any suitable means indicated at 55, and thevanode is stretch'edby the device 30 until the predetermined desired capacity is indicated. At this' time the tool will be removed'and the anode I2 will remain in the position to which it has been stretched.

The tool 36 may also be used to adjust the capacity between the cathode I4 and the grid I6. In Fig.- 1, Lhave shown, by way of example, a cathode structure in which the cathode proper 58 is supported in any suitable manner up'on a head 56 which, in turn, is connected to the n- `velope through a bowed-out base 60. In this form of construction the bottom of the base 68 is formed withy an integral collar 62 having a suitable abutting surface 64, which will function similarly to the attached collar 26 illustrated in connection with the anode I2. Suitable heater leads 66 can be provided, passing through the transverse portion 68 of the head 56. It will be clear to those skilled in this art that adjusting of the cathode structure l58 by the tool 30 will take place similarly to the aforedescribed adjusting of the anode structure I2. In this case the dogs 44 will abut the surface 64 of the collar 62,

while the plunger 36 will bear against the transverse portion 68 of the head 56. Actual stretching of the electrodeA structure takes place in the thin bowed-out base 66, this base being stretched by the tool 30 until the desiredcapacity between the cathode element 58 and the grid I6 is indicated upon the measuring device. 1 While a corrugated base with an attached collar has been illustrated in connection with the anode structure I2, and a bowed-out base with integral collar 'has been illustrated in connection with the cathode structure I 4, it is to be underv 4 understood that changes may be made as will be apparent to those skilled in this art.

What I claim is:

1. An electron discharge device including an envelope, a'nrst electrode structure and a second electrode structure mounted in said envelope, said second electrode structure having a head portion positioned adjacent said nrst electrode structure and in capacitativerelationship therewith and a longitudinally extensible .ibase attached to said envelope, and removable adjustable means engaging within said second electrode structure for stretching said extensible base and moving said head toward said rst electrode vstructure until a predetermined capacity between the same has been attained.

generally cylindrical hollow envelope, an electrode extending across said envelope and positioned substantially centrally between its ends, and a pair of additional electrodes, one mounted in each end of said envelope, each of said additional electrodes having a head portion positioned within said envelope and in capacitative relation with the central electrode, and each of said additional electrodes having a longitudinally extensible base attached to an end of the envelope, whereby the distance between the head of each of said additional electrodes and the central electrode may be adjusted by the longitudinal' expansion of its respective base to vary the capacity between the corresponding electrodes.

4. An electron discharge device including an envelope, a rst electrode structure and a second electrode structure mounted in said envelope, said second electrode structure ,having a head portion formed as a hollowcylinder, positioned adjacent said rst electrode structure and 1n capacitative relationship therewith, and a longitudinally extensible base formed with an internal shoulder at its lower end and attached to said envelope, and removable means inserted within said second electrode structure for stretching said extensible base and `moving saidvhead toward said rst electrode structure until a predetermined 'capacity between the same has been attained, said means including a plurality of radially extensible ngels having dogs abutting longitudinally against said shoulder, and a longitudinally movable plunger engaging the inside of said head for moving the latter relatively to said internal shoulder.

5. An electron discharge device including an envelope, a nrst electrode structure and a second electrode structure mounted in said envelope, said second electrode structure having a head portion stood that these structural details are interchangeable. For example, the integral collar can 4be used in connection with the corrugated base or the inserted collar with the bowed-out base. The cathode and anode structures may be formed alike or differently.

It will also be clear to those skilled in this art that the principles of the present invention are not confined to the exact type of electron discharge device illustrated but, on the other hand, are readily applicable to all types of electron dis- Y charge devices in which it is desired to obtain an accurate capacitative relationship between longitudinally related electrodes.

While certain preferred forms oi' construction have been illustrated and described, it is tobe formed as a hollow cylinder, positioned adjacent said rst electrode structure and in capacitative relationship therewith, and a longitudinally ex` tensible base formed with an internal shoulder at its lower end, attached to said envelope, and removable means inserted within said second electrode structure for stretching said extensible base4 operable from without the envelope for moving said plunger against the inside of the head portion against the reaction oi said dogs on said shoulder for stretching the head portion of the electrode relatively to said shoulder.

WILLIAM HOTINE.

REFERENCES CITED The following references are of record in the le of this patent:

Number UNITED STATES PATENTS Name Date Linder Feb. 25, 1941 Lilienfeld Nov. 3, 1925 Dallenbach July 25, 1939 Knoll Apr. 27, 1937 Pohl Jan. 27, 1931 Bieling Feb. 15, 1938 

